October 17, 2014

Marking the completion of a record-setting journey, the U.S. Air Force X-37B spacecraft returned to Earth on Friday by making a flawless landing at Vandenberg Air Force Base, California. This latest mission of the semi-classified spaceplane was 22 months in duration, eclipsing its two previous flights that lasted 7 and 16 months. The purpose of the third X-37B mission was not disclosed to the public and OTV-3 flew in an orbit that was not publicly announced.

The secretive OTV-3 mission began on December 11, 2012 when the spacecraft was launched atop an Atlas V 501 rocket that successfully delivered the vehicle to its planned orbit. The OTV-3 mission was performed by the X-37B that flew the first OTV mission in 2010 lasting 224 days after which the craft was refurbished for another mission within two years.

The X-37B is manufactured by Boeing Phantom Works for operation by the United States Air Force used for secret applications that likely include testing of new technologies such as surveillance systems, communications technology, or electronic intelligence systems.

Photo: Boeing

As a craft that returns from extended missions to space, X-37B is ideally suitable to test materials in space and conduct experiments in orbit before returning the hardware to Earth for post-flight analysis and potential use in future spaceflight applications.

Image: Boeing Phantom Works

Photo: Boeing

Analysts believe that the X-37B is used to test out Space Awareness Sensors or Earth Observation Payloads. Since the ground track of OTV-3 did not repeat at the frequent intervals seen for OTV-1 and 2, it is probable that whatever resided inside the vehicle’s payload bay was looking at space instead of Earth.

Overall, the X-37B, that resembles a miniature Space Shuttle Orbiter, measures 8.9 meters in length, has a wingspan of 4.5 meters and a launch mass up to 4,990 Kilograms. The craft has a 2.1 by 1.2-meter payload bay protected by doors that open once launched into orbit and close in anticipation of landing. Power generation is accomplished by a single deployable solar array and a reaction control system and main propulsion system enable the X-37B to conduct frequent orbital maneuvers as demonstrated on its previous missions. The underside of the vehicle is covered in silica ceramic tiles to protect it during re-entry.

Following its successful launch, OTV-3 was quickly spotted in orbit by satellite trackers around the world who kept track of this and the previous X-37B flights. OTV-3 was delivered to an initial orbit of 345 by 363 Kilometers inclined 43.5 degrees which is an orbit lower than that of OTV-1, but higher than that of OTV-2. Unlike the previous two X-37B missions, OTV-3 did not perform frequent orbital maneuvers and remained at an altitude between 350 and 410 Kilometers for most of its mission, maintaining the orbit by using its propulsion system.

The exact purposes of the OTV-3 mission and that of its predecessors were not released to the public. "This mission will incorporate the lessons learned during the refurbishment process on OTV-1," said X-37B program manager Lieutenant Colonel McIntyre before the OTV-3 mission.

"As the X-37B program is examining the affordability and reusability of space vehicles, validation through testing is vital to the process. We are excited to see how this vehicle performs on a second flight. As with previous missions, actual duration will depend on the execution of test objectives, on-orbit vehicle performance, and conditions at the landing site."

Known from OTV-2, the X-37B can surpass its design life of 270 days per mission, however, OTV-3 set out to complete a much longer mission, passing the mark of OTV-2 and continuing operations in orbit for several more months. Last week, the Air Force announced that preparations for the landing of the OTV-3 spacecraft were underway at Vandenberg Air Force Base. Prior to that announcement, X-37B lowered its orbit to 259 by 286 Kilometers, in-line with previous OTV missions that included a similar orbital adjustment leading up to landing. Initial air space closures were announced for Tuesday, however, the landing slipped - likely due to local weather conditions. New air space closures were issued for Wednesday and Thursday, but were canceled in the morning hours, local time, after the landing was waived off.

On Friday, OTV-3 retracted its solar array, closed its payload bay doors and fired its 700-Newton main engine in a retrograde attitude to slow the vehicle down in order to intercept the atmosphere at a pre-determined location.

Hitting the atmosphere, X-37B conducts banking maneuvers to dissipate energy and begin targeting its runway at Vandenberg Air Force Base in California using GPS data.Continuing to fly on autopilot, X-37B made a controlled glide en-route to the runway threshold. Deploying its main and nose gear, the spacecraft flared up its nose and made a smooth touchdown on Runway 12 at 16:24 UTC - returning to Earth after 674 days & 22 hours. Coming to a stop, X-37B was attended to by technicians that began to safe the spacecraft following its successful landing.

Over the coming months, OTV-3 will have its payloads removed for post-flight analysis and begin the process of being refurbished for a future mission – potentially based at the Kennedy Space Center where Boeing has begun preparing two of the former Space Shuttle Orbiter Processing Facilities for ground operations of its spacecraft.

Photo: Boeing

This would allow future X-37B mission to launch from Cape Canaveral and land at the Shuttle Landing Facility for a short tow-back to the processing facility, eliminating the cross country trip that had been part of previous OTV missions that launched and landed at opposite coasts of the United States.

The next X-37B mission is planned to launch in 2015.

Classified X-37B Space Plane passes 500 Days in Orbit

April 24, 2014

Image: Boeing Phantom Works

The mysterious X-37B spacecraft has passed the milestone of spending 500 days in orbit on its semi-secret OTV-3 mission. No details on the current mission of the X-37B have been released by the US air Force, the operator of the clandestine space plane. It is not known when the vehicle will return to Earth, making an automated landing on a runway.

OTV-3 was launched atop a United Launch Alliance Atlas V 501 rocket back on December 11, 2012, embarking on a classified mission carrying a suite of secret payloads, presumably for testing in the space environment before returning to Earth for examination. X-37B has made two previous flights – OTV-1 was flown in 2010 by the vehicle currently in space while OTV-2 used the second X-37B vehicle in 2011/12. Originally built for missions up to 270 days, X-37B spent 224 days in orbit on its first mission and its second flight already surpassed its design mission, orbiting Earth for 468 days. Setting a new longevity record, OTV-3 has now spent 500 days in its classified orbit.

Shortly after its launch, the spacecraft was spotted by amateur satellite trackers in an orbit of 345 by 363 Kilometers at an inclination of 43.5 degrees.

Once the spacecraft had been spotted, satellite trackers around the globe kept tabs on the vehicle, following its orbital maneuvers to keep track of the X-37B since its orbit is not officially released. Unlike the OTV-1 mission that featured numerous orbital maneuvers, OTV-3 has not shown significant activity in terms of maneuvers. The vehicle maintained its orbit throughout the mission with occasional engine burns and was last tracked in an orbit of 382 by 406 Kilometers.

Given that the vehicle did not expend as much propellants for orbit lowering and raising maneuvers like OTV-1 did, it likely has a large reserve of propellants left that would permit the mission to continue for some time. Otherwise, the vehicle is not dependent on any consumables since power generation is accomplished by a deployable solar array.

The US Air Force has stated that the vehicle is intended to demonstrate reusable space technologies and fly experiments to space, but the exact objectives of the vehicle and its missions are kept secret. The X-37B is 8.9 meters long, 2.9 meters tall and has a wingspan of 4.5 meters. It has a loaded weight of ~4,990 Kilograms. More details can be found here.

The payload bay of the X-37B is 2.1 by 1.2 meters in size, offering space to different payloads for testing in the space environment before being returned to Earth when the mission is complete and all objectives are met. Analysts believe that the X-37B is used to test out Space Awareness Sensors or Earth Observation Payloads. Since the ground track of OTV-3 does not repeat at the frequent intervals seen for OTV-1 and 2, it is probable that whatever resides inside the vehicle’s payload bay is looking at space instead of Earth.

Once the OTV-3 mission is complete, the spacecraft will perform a deorbit burn and return to Earth for post-flight analysis of the secret payload. X-37B can land at Vandenberg Air Force Base and Edwards AFB, California, but the Kennedy Space Center’s Shuttle Landing Facility is not out of the question for future X-37 landings. Some have speculated that OTV-3 is being kept in orbit longer to allow time for Boeing to prepare Orbiter Processing Facility 1 at the Kennedy Space Center for X-37B ground operations.

Photo: Boeing

OPF-1 was handed over to Boeing for
X-37B refurbishment in between flights to allow the
spacecraft to launch and land at Cape Canaveral avoiding the
cross-country trip that had been part of the previous OTV missions.

It remains to be seen where and when the X-37B will land after completing its OTV-3 mission - there had been speculation that the Air Force aims to keep the vehicle in orbit for two years. The Air Force will officially declare mission success shortly after landing of the spacecraft.

"This mission will incorporate the lessons learned during the refurbishment process on OTV-1," said X-37B project manager Lieutenant Colonel McIntyre after the launch of OTV-3. "As the X-37B program is examining the affordability and reusability of space vehicles, validation through testing is vital to the process. We are excited to see how this vehicle performs on a second flight. As with previous missions, actual duration will depend on the execution of test objectives, on-orbit vehicle performance, and conditions at the landing site."

Satellite Trackers spot the X-37B (OTV-3) in its classified Orbit

December 12, 2012

After Tuesday’s successful launch of the X-37B Orbital Test Vehicle 3 atop an Atlas V 501 Rocket blasting off from Cape Canaveral Air Force Station, Satellite Trackers have successfully observed the vehicle for the first time.

Tuesday’s successful launch began the third mission of the X-37B, the second flight of this particular vehicle that also flew the OTV-1 mission in 2010. It also marked the first time a re-usable space vehicle was launched atop an Expendable Launch Vehicle to make its second trip to space.

"We couldn't be more pleased with the strides we've made in this program and the success of the X-37B vehicle on the first two flights," said Mr. Richard McKinney, Deputy Under Secretary of the US Air Force for Space. "However, it is important to keep in mind that this is an experimental vehicle and a third mission is still relatively young for a test program. This is the first re-flight of a vehicle so that is certainly a key objective for us. We have only just begun what is a very systematic checkout of the system."

Image: Boeing Phantom Works

After making its successful launch and orbital insertion, OTV-3 received its military designation: USA-240. The OTV-3 mission is a classified flight, as were the previous two flights of the X-37B. No details about the vehicle’s payloads, orbit and mission duration were disclosed to the public.

Following Tuesday’s Atlas V launch, Satellite Trackers around the world started watching the sky to look for OTV-3. The first reported observation came from Greg Roberts, as reported on the SeeSat-L mailing list. Roberts observed the Centaur Upper Stage and OTV-3 just 19 minutes after Main Engine Cutoff 1 on the Centaur at T+17:34. Well known Satellite Tracker Ted Molczan used data acquired during this first observation of OTV-3 to compute its orbit. According to Molczan, OTV-3’s initial orbit is 345 by 363 Kilometers with an inclination of 43.497 degrees. Refer to Molczan’s Update at SeeSat for OTV search elements.

This orbit is slightly higher than the initial orbit of OTV-2 (317 x 319km at 40 deg) and lower than that of OTV-1 (403 x 420km at 42.9 deg). Why there was a Dogleg maneuver built into the OTV-3 launch sequence remains unknown as an orbital inclination of 43.5 degrees can be reached by launches from Florida’s space coast.

What lies ahead for OTV-3 is classified. It is expected that the vehicle will stay in space for several months performing a number of orbit adjustment maneuvers, but with its initial orbit and final inclination known, Satellite Trackers will not have much trouble keeping track of OTV-3 throughout its mission that is planned to build on the success of the first two OTV flights.

"This mission will incorporate the lessons learned during the refurbishment process on OTV-1," said Lieutenant Colonel McIntyre, X-37B program manager. "As the X-37B program is examining the affordability and reusability of space vehicles, validation through testing is vital to the process. We are excited to see how this vehicle performs on a second flight. As with previous missions, actual duration will depend on the execution of test objectives, on-orbit vehicle performance, and conditions at the landing site."

Semi-Secret X-37B in Orbit after successful Atlas V Launch

December 11, 2012

Photo: United Launch Alliance

United Launch Alliance and the US Air Force Rapid Capabilities Office have successfully launched the X-37B OTV-3 aboard a ULA Atlas V 501 launch vehicle blasting off from Space Launch Complex 41 at Cape Canaveral Air Force Station at 18:03 UTC on Tuesday – starting a classified flight in Low Earth Orbit.

After Monday’s Rollout of the Atlas V from its integration facility to the launch pad, teams got the vehicle ready for Countdown Operations that started early on Tuesday, local time. The Launch Team was on console at L-7:30, and 15 minutes later, the Atlas V Launch Vehicle was powered up to begin final testing and countdown activities. In the early portion of the countdown, teams cleared the Vehicle Integration Facility, performed Launch Pad Close-Outs and started to set up Road Blocks in preparation for Blast Danger Area Evacuation. After completing vehicle and pad close-outs, engineers departed the Launch Complex and cleared the Blast Danger Area to set the stage for the complex fueling process. Also, the Launch Hazard Area became active and Air Force Controllers started to monitor the Eastern Range.

Checkouts and reconfigurations of the Atlas V 501 launcher continued as planned. In its 501 configuration, the launcher is equipped with no Solid Rocket Boosters, has a single-engine Centaur Upper Stage and uses a five-meter payload fairing. With its two stages, Atlas V 501 stands more than 62 meters tall and has a main diameter of 3.81 meters. Visit our Launch Vehicle Overview for all specifications and details about Atlas V 501.

On Tuesday, Atlas V had a total of three launch opportunities, all being 10 minutes in duration with the first window opening at 18:03 UTC.

Fueling got underway just after countdown clocks started ticking again coming out of a 30-minute built-in hold at the T-2-Hour mark.This hold was the first of two built-in countdown holds.Tuesday's Atlas V Countdown featured an extended hold of 20 minutes at T-4 minutes to give teams additional time to make final launch preparations and deal with any off-nominal situations. When clocks started ticking again, the complex cryogenic propellant loading operation started. The procedure began with Transfer Lines Chilldown and Atlas/Centaur Tank Chilldown before propellants started actually flowing inside the Vehicle’s tanks.

Liquid Oxygen Loading of the Centaur Upper Stage began on time at L-2 hours and 8 minutes and was followed by Common Core Booster LOX Tanking at approximately L-1 Hour and 53 Minutes. To fill the tanks with Oxidizer, the vehicle went through slow fill mode before transitioning to fast-fill and eventually reaching the topping phase when tanks crossed the 95% mark. Atlas Booster Topping began while the Upper Stage had reached its LOX Flight Level. Centaur Liquid Hydrogen Loading started at L-82 Minutes and also went through the nominal steps. Only cryogenics had to be tanked today, since the Rocket Propellant 1 Fuel, which is rocket-grade Kerosene, was loaded as part of pre-countdown operations. In total, the launcher was holding 304,919 Kilograms of propellants when fueling was complete. The hydraulic system of the vehicle was pressurized and checked and the RD-180 first stage engine as well as the RL-10 second stage engine were put through a steering profile. At L-50 minutes, the Fueling Process concluded and a final round of vehicle testing started. These tests included Flight Termination System checks to make sure the system was ready to destroy the launcher in the unlikely event of a major malfunction.

At T-4 Minutes, countdown clocks stopped once again for the final built-in hold which was 20 minutes in duration, 10 minutes longer than usual to give the Launch Team additional time to deal with any issues. During the hold, teams performed final checkouts and verifications before the final set of polls came up. Also, the X-37B Spacecraft was switched to internal power at L-5 Minutes. The launch team was polled for a Go/No Go to resume the Countdown and Launch. All Stations Reported GO, including Range Weather as teams beat the bad weather odds of only a 30% chance of favorable conditions during Tuesday’s launch windows. Clouds were coming in from the South-West, bringing showers and thunderstorms, but luckily, the front was at a safe distance for launch, not violating any weather rules.

The Countdown resumed at 17:59 UTC and final vehicle reconfigurations were made in the 4 minutes leading up to Blastoff. Pressurization of Atlas and Centaur Tanks to Flight Level was completed as expected. Also, the vehicle switched to internal power and the Launch Control System was enabled. (Countdown Timeline) The single, 2-chamber RD-180 Main Engine of the Atlas Rocket soared to life and was allowed to reach full thrust while being closely monitored by flight computers. After nominal engine performance was verified, the Launcher was allowed to blast off.

At precisely 18:03:00 UTC, the Atlas V 501 launcher blasted off from SLC-41 roaring into a cloudy space coast sky. At a Thrust-To-Weight Ratio of just 1.157 at Liftoff, the initial portion of the Atlas V has given the usual slow impression before the launcher picked up speed and soared into the sky.

Initially, the Atlas V completed a short vertical ascent for about 18 seconds before starting its roll and pitch maneuver to align itself with its precise ascent trajectory to meet its cutoff target. The RD-180 on the Common Core Booster provides 3,827 Kilonewtons of liftoff thrust. As the vehicle ascended, it passed Mach 1 at T+83 and Maximum Dynamic Pressure at T+89 seconds. First stage performance was nominal as the RD-180 was commanded to throttle down for Payload Fairing jettison. With X-37B’s aerodynamic shape and thermal protection system, the Payload Fairing can be jettisoned much earlier because the vehicle can tolerate atmospheric stress. Separating the fairing as early as possible increases launch vehicle performance as extra-weight is lost by jettisoning the PLF. As usual for X-37B Flights, Atlas V used its short 5-meter fairing which is 5.4 meters in diameter and 20.7 meters long with a mass of 3,524kg. PLF jettison occurred at T+3:36, followed a few seconds later by Forward Load Reactor Jettison.

The first stage continued to burn until T+4:23, consuming a total of 284,000kg of cryogenic propellants. Stage Separation came six seconds later and was clean. Shortly thereafter, the RL-10B-4-2 engine on the Centaur Upper Stage went into pre-start before reaching full Thrust. MES-1, Main Engine Start 1, occurred at T+4:39. The first burn of the Centaur had a duration of 12 minutes and 55 seconds. Centaur is 3.05 meters in diameter, 12.68m long and holds 20,830kg of propellants at liftoff. Its RL-10 engine, the reason for the lengthy launch delay this mission suffered, provides a vacuum thrust of 99.2 Kilonewtons.

After Centaur Shutdown at T+17:34, the mission headed into the nominal news blackout due to the semi-secret nature of the X-37B program. There is a consensus that the vehicle only requires a single Centaur engine firing to reach its intended and classified orbit, so that Spacecraft Separation is the only event that is not reported live. After delivering the X-37B to orbit, Centaur makes its regular Collision Avoidance Maneuvers before starting its RL-10 engine again for a brief Deorbit Burn to set the stage for its destructive re-entry above the Indian Ocean.

Photo: United Launch Alliance

Photo: United Launch Alliance

About one hour after launch, ULA announced mission success: "The ULA team is proud to have played a critical role in successfully launching these three important Orbital Test Vehicle missions for the Air Force RCO," said Jim Sponnick, ULA vice president of mission operations. "This is a unique spacecraft since it is the first to launch on an Atlas 5, return to Earth landing at Vandenberg Air Force Base in California, and then fly again on this mission."

*File Image* - Photo: US Air Force

Image: Boeing Phantom Works

What is ahead for the X-37B is top secret. The Boeing X-37B, also called X-37 Orbital Test Vehicle – OTV – is a reusable unmanned spacecraft that is manufactured by Boeing and operated by the United States Air Force. The US Air Force has stated that the vehicle is intended to demonstrate reusable space technologies and fly experiments to space, but the exact objectives of the vehicle and its missions are kept secret. The X-37B is 8.9 meters long, 2.9 meters tall and has a wingspan of 4.5 meters. It has a loaded weight of ~4,990 Kilograms. More details can be found here.

As usual, no details on the mission’s payload, orbital trajectory and duration have been released. OTV-3 will start out in a Low-Earth Orbit somewhere between 300 and 400 Kilometers in altitude, but over the course of its mission, the spacecraft will perform a number of larger and smaller orbit adjustments. The duration of the OTV-3 mission is also not known. X-37B is rated to stay in space for 270 days, but as OTV-2 has shown, the vehicle is capable of significantly exceeding this mission duration. The OTV-2 mission had a duration of 468 days and 13 hours.

This third flight of the X-37B is being flown by the vehicle that completed the OTV-1 mission in 2010 to demonstrate the re-usability of the X-37. This particular vehicle spent 224 days and 9 hours in space during the first flight of the X-37B. Once the OTV-3 mission is complete, the spacecraft will perform a deorbit burn and return to Earth for post-flight analysis of the secret payload. X-37B can land at Vandenberg Air Force Base and Edwards AFB, but the Kennedy Space Center’s Shuttle Landing Facility is not out of the question for future X-37 landings.

With the launch of this mission, Satellite Trackers around the world will be watching possible Low Earth Orbit slots to identify the vehicle and keep track of it throughout its mission. For the previous flights, satellite trackers were able to spot X-37B within days and keep track of its orbital maneuvers throughout its mission. Ted Molczan has issued search elements based on the OTV-2 flight.

Whether OTV-3 is in a similar orbit or flying at a different inclination will be answered when the spacecraft is spotted. Initial reports of OTV-3 sightings already came in within 90 minutes after launch. During the public launch webcast provided by ULA, it was announced that the Atlas V completed a Dogleg Maneuver during its ascent. A Dogleg is a guided, powered turn during the ascent phase of a Rocket Flight – which is not done without having a good reason as it comes at the cost of launch vehicle performance to the intended orbit.

Today’s Atlas V mission marked the 616th launch of an Atlas since the beginning of the program in the 1950s. It was the 34th launch of an Atlas V, the 4th flight of the 501 vehicle configuration and the 6th Atlas launch of 2012.

Atlas V & X-37B rolled to Launch Pad for Liftoff on Tuesday

December 10, 2012

A United Launch Alliance Atlas V 501 Rocket with X-37B OTV-3 under its Payload Fairing has been rolled out to Space Launch Complex 41 at Cape Canaveral Air Force Station, Florida, to set the stage for final launch preparations for liftoff on Tuesday.

To make the first 550-meter trip to its classified Orbit, the Launcher and the X-37B Spacecraft hidden under the Atlas V Payload Fairing was rolled from the Vehicle Integration Facility to the nearby launch pad. The move started in the morning hours, local time, on Monday and the large Mobile Launch Platform was transported using two trackmobiles. The trip from the VIF to the launch site took about 30 minutes and was completed at 15:50 UTC with the Platform being centered on the Pad. Once arriving at the Launch Pad, a busy day of launch preparations got underway as the vehicle was secured at its launch site. Electrical connections are being made and propellant and communication lines are connected. Later, the trackmobiles are removed and pad close-outs start to set the stage for countdown operations on Tuesday.

Countdown operations will begin 7 hours before launch with Launch Vehicle Activation. Subsequently, initial checks of the Atlas Launcher will be made and the Launch Area will be cleared off all personnel. At T-2 Hours, the cryogenic tanking process will start as the first stage is filled with Liquid Oxygen and the second stage is loaded with Liquid Hydrogen and Liquid Oxygen – going through a complex tanking procedure involving slow and fast propellant fill followed by topping and replenish. While the countdown continues, final systems checks will be performed by the Launch Team. Final Flight Software will be loaded into the flight computers aboard the Atlas and countdown clocks will stop at the T-4-Minute Mark to give teams a chance to address any open issues and conduct the final GO/No GO Polls setting the stage for Launch. As clocks start ticking down from T-4 Minutes, final vehicle configurations will be made as part of the Automated Sequence to place the vehicle in its launch configuration.

Photo: United Launch Alliance

Liftoff is planned to occur at some point in a classified window opening at 18:03 UTC. The vehicle can lift off no later than 23:03 UTC

Weather conditions are still predicted to be 30% favorable for Tuesday’s and Wednesday’s launch opportunities. “High pressure continues to migrate east today in advance of the next cold front pushing into the Florida panhandle Monday evening. The front is near Central Florida Tuesday evening with a disturbed and unsettled weather pattern on Tuesday and Wednesday. The front remains near stationary over Central Florida through Wednesday and slowly pushes through Central Florida Thursday morning. There is the potential for thunderstorms on Tuesday and Wednesday to be strong to severe with very high moisture in-place, warm temperatures, instability, and mid and upper level dynamics,” the 45th Weather Squadron Launch Forecast notes.

In case of unfavorable weather conditions at the opening of the launch window, teams will incrementally delay the T-0 time, continuously monitoring weather conditions to see whether conditions are clearing up and launch criteria are GO.

An Atlas V Countdown Timeline is available here.S101_Live will provide real-time updates of the final countdown phase and ascent. United Launch Alliance will provide a live webcast starting 20 minutes ahead of the opening of the launch window. Due to its classified nature, the mission will head into a news blackout at the conclusion of the first Centaur Upper Stage Burn.

Time
(h:mm:ss)

Event

-0:00:02.7

Stage 1 - RD180 Ignition

00:00:00

Engine Ready

+0:00:01.1

Liftoff

+0:00:02.1

Full Thrust Level

+0:00:18.3

Pitch/Roll Maneuver Initiation

+0:01:23.1

Mach 1

+0:01:29.1

Maximum Dynamic Pressure

+0:03:36.1

Payload Fairing Jettison

+0:03:41.6

Forward Load Reactor Jettison

+0:04:23.2

Stage 1 Cutoff

+0:04:29.2

Atlas/Centaur Separation

+0:04:39.2

Centaur Ignition 1

Burn Duration: 12:55.3

+0:17:34.5

Centaur Cutoff 1

News Blackout

X-37 and Atlas V ready for Launch on Tuesday after Weeks of Delays

December 9, 2012

*File Image* - Photo: United Launch Alliance

United Launch Alliance is working toward a December 11 launch target of its Atlas V 501 Rocket for the third flight of X-37B Orbital Test Vehicle 3 after teams cleared the RL-10 engine for launch, completing analysis of the previous issues the engine exhibited. Problems with the RL-10 engine emerged on its most recent flight, when a Delta IV Medium+ (5,2) launched from Cape Canaveral to deliver the GPS-IIF3 Satellite to Medium Earth Orbit. During the flight, the RL-10 engine exhibited an underperformance issue resulting in burns being longer than planned to achieve the desired orbital velocities. ULA said in a post-flight statement "a lower than normal chamber pressure was observed." The Guidance, Navigation and Control System of the launch vehicle was able to adjust its ascent profile to respond to the problem, extending its engine burns to meet the required velocities needed to reach the particular transfer/parking orbits. Luckily, the GPS-IIF3 flight had plenty of margin, because launch vehicle performance for the GPS Medium Earth Orbit exceeded that required to deliver the payload to this orbit. The launch did not end in failure only because this particular launch had excess performance, providing the margin needed to make it to the target orbit. With a heavier payload closer to the Launch Vehicle's limits, the mission would have ended differently due to the additional fuel consumption of the upper stage. It is not exactly known whether OTV-3 is closer to the Atlas V limit due to its varied weight and unknown target orbit, but teams did not want to launch an RL-10 engine before all details about the issue observed on the Delta IV flight were known and concerns were cleared. "Although the GPS mission was successful and the satellite was delivered to a precise orbit, ULA and Pratt & Whitney Rocketdyne (PWR) are executing an extremely robust investigation into the cause of the reduced engine performance on the recent Delta IV mission,” said Jim Sponnick, ULA vice president, Mission Operations.

Although, Atlas V and Delta IV use different models of the RL-10, ULA and the US Air Force have decided to complete all assessments prior to the next launch of an RL-10 since the different variants share a number of components. The Delta Cryogenic Upper Stage uses an RL-10B-2 that features a nozzle extension and electro-mechanical gimbaling systems. It provides 110 Kilonewtons of nominal thrust and has a specific impulse of 462s. The Centaur Upper Stage of the Atlas V is equipped with a (more conventional) RL-10A-4-2 engine that provides 99.1kN of thrust and has an Isp of 451s. More information about the RL-10 can be found on the Delta IV and Atlas V Launch Vehicle Information sites.

The investigation was in progress for several weeks, but concluded in time to get OTV-3 off the ground before the end of the year. "The ULA investigation has concluded that a fuel leak occurred in a specific area of the interior of the thrust chamber, and that this leak started during the first engine start sequence," ULA said in a recent statement. The investigation into the flight data anomaly will continue, but ULA teams were able to complete necessary crossover investigations between the two different RL-10 models used on Atlas and Delta IV. “Our flight data anomaly investigation includes substantial involvement and oversight from senior industry technical advisors, as well as our Air Force OTV customer, Air Force EELV customer, and NASA customers,” added Sponnick. “We thank the OTV customer for their patience and participation throughout the flight clearance process for this important mission.”

Clearance for the Atlas V was provided and teams began to work toward the next launch of the vehicle.

OTV-3 is set for launch on Tuesday, December 11, 2012 at some point in a 5-hour launch window stretching from 18:03 UTC to 23:03 UTC. The launch target has been cemented by the Launch Readiness Review that was performed on Friday and dealt with any remaining issues or open items, with mission managers discussing all elements of the Launch Vehicle, the Payload and the Ground Support Equipment to make sure all systems were ready for the mission. The green light to press into final launch operations was given.

The Launcher will be moved to Space Launch Complex 41 at Cape Canaveral Air Force Station on Monday for final launch preparations and the Launch Countdown. Two trackmobiles will be used to move the Mobile Launcher and the Atlas V with its Payload to the Launch Pad. Rollout will take approximately 30 minutes. When arriving at the Pad, the structure will be secured and electrical connections will be made. Also, propellant and communication lines will be connected. Later, the trackmobiles will be removed and pad close-outs will start to set the stage for countdown operations.

Currently, there are no reports of any technical issues, but weather might be an issue. Meteorologists have issued a 30% chance of favorable conditions on Tuesday. For the backup launch slot on Wednesday, odds are similar. Primary concerns are cloud rule violations and isolated thunderstorms in the area violating launch commit criteria.

X-37B OTV-3 Launch continues to slip - Now NET December

November 21, 2012

The next launch of the X-37 on Mission OTV-3 aboard a United Launch Alliance Atlas V 501 is continuing to slip to the right. "The new planning date for the launch of an Atlas V carrying the third X-37B Orbital Test Vehicle (OTV-3) payload for the U.S. Air Force is Dec. 11, 2012, pending approval from the range," ULA said in a statement. Whether December 11 actually becomes a launch target rather than a NET date (No Earlier Than) depends on the progress of the ongoing investigation of the RL-10 Upper Stage Engine that misbehaved on its last flight in October when a Delta IV carried the GPS IIF-3 Satellite to Medium Earth Orbit. For more details about the failure and subsequent analysis, refer to previous updates below on this site.

Next X-37B Mission slips to November 27

November 3, 2012

Photo: Boeing Phantom Works

The Launch of a United Launch Alliance Atlas V 501 with X-37B OTV-3 has been delayed further and is now rescheduled for November 27, 2012, ULA said in a press release on Friday. Initially, the launch was delayed to October 30, then is slipped to November 13 and now it is scheduled for the 27th. These delays have become necessary to give teams time to complete required analysis of the RL-10 engine underperformance on its most recent flight on a Delta IV that delivered GPS IIF-3 to Medium Earth Orbit on October 4. "Although the team investigating the lower than normal upper-stage engine chamber pressure from the recent Global Positioning System (GPS) IIF-3 launch has been making good progress reviewing and analyzing the data, ULA leadership and the Air Force have decided to postpone the launch two weeks to allow for additional flight data anomaly investigation activities and a thorough crossover assessment for the X-37B OTV launch vehicle to be completed," the ULA statement said.

The Delta Cryogenic Upper Stage uses an RL-10B-2 that features a nozzle extension and electro-mechanical gimbaling systems. It provides 110 Kilonewtons of nominal thrust and has a specific impulse of 462s. The Centaur Upper Stage of the Atlas V is equipped with a (more conventional) RL-10A-4-2 engine that provides 99.1kN of thrust and has an Isp of 451s. Teams are currently reconstructing data acquired on the Delta IV flight to assess the exact performance of the engine and determine the cause of its underperformance. In addition, teams are completing extensive inspections of present engines including that of the Atlas V 501 launcher that is planned to boost the X-37 into orbit. This is done to make sure any problems that occurred with the Delta IV RL-10 are not present on any other engines. For that, the manufacturing process and used materials are examined.

The next launch of the Atlas V on its busy manifest has slipped to January 2013 as a result of the delays of this flight. An Atlas V 401 is set to carry Tracking and Data Relay Satellite-K to orbit for NASA, but the launcher and its payload have to wait until the Launch Facility is vacated by OTV-3 to begin integration at Space Launch Complex 41 at Cape Canaveral Air Force Station.

X-37B OTV-3 Launch delayed by RL-10 Engine Investigation

October 20, 2012

The Launch of the third X-37 Orbital Test Vehicle Mission has been delayed further to allow United Launch Alliance to complete its ongoing investigation of the Upper Stage problem that occurred during the company's most recent mission of a Delta IV rocket with GPS IIF-3. Initially, the launch was delayed to October 30, but on Friday, ULA announced that the launch from Cape Canaveral Air Force Station's Space Launch Complex 41 is pushed back to at least November 13. During the launch of the Delta IV Medium+ (4,2), the first and second Upper Stage Burns were longer than planned indicating an under-performance issue on the RL-10 upper stage engine - which was confirmed by ULA that noted that "a lower than normal chamber pressure was observed." The Guidance, Navigation and Control System of the launch vehicle was able to adjust its ascent profile to respond to the problem, extending its engine burns to meet the required velocities needed to reach the particular transfer/parking orbits.

Atlas V *File Image* - Photo: United Launch Alliance

A third burn of the upper stage was completed satisfactory and the GPS satellite was delivered to its planned orbit, but only because this particular launch had excess performance, providing the margin needed to make it to the target orbit. With a heavier payload closer to the Launch Vehicle's limits, the mission would have ended differently due to the additional fuel consumption of the upper stage.

Although, Atlas V and Delta IV use different models of the RL-10, ULA and the US Air Force have decided to complete all assessments prior to the next launch of an RL-10 since the different variants share a number of components. The Delta Cryogenic Upper Stage uses an RL-10B-2 that features a nozzle extension and electro-mechanical gimbaling systems. It provides 110 Kilonewtons of nominal thrust and has a specific impulse of 462s. The Centaur Upper Stage of the Atlas V is equipped with a (more conventional) RL-10A-4-2 engine that provides 99.1kN of thrust and has an Isp of 451s. More information about the RL-10 can be found on the Delta IV and Atlas V Launch Vehicle Information sites.

X-37B getting ready for third classified Flight

October 1, 2012

*File Image* - Photo: US Air Force

United Launch Alliance and the United States Air Force are gearing up for the next Mission of the semi-secret X-37B Orbital Test Vehicle. The small spaceplane will be launched aboard an Atlas V Launch Vehicle flying in its 501 Configuration. Liftoff from Space Launch Complex 41 at Cape Canaveral Air Force Station is planned for October 25, 2012 and OTV-3 will be delivered to a classified Low Earth Orbit to begin its mission of several months. Launch preparations at SLC-41 began in early September. The Common Core Booster of the Atlas V Launcher was rolled to the Vertical Integration Facility on September 13 and the Boosters was installed atop the Mobile Launch Platform. After the 285-Kilogram CBC-Centaur Interstage Adapter was installed, the Centaur Upper Stage was mounted on top of the vehicle. After the launcher was fully integrated, teams began testing of the vehicle to make sure it is ready for launch and payload installation. The X-37B will be encapsulated in its 5.4-meter diameter Payload Fairing before being moved to the Launch Complex. This third flight of the X-37B will be flown by the vehicle that completed the OTV-1 mission in 2010 to demonstrate the re-usability of the X-37. This particular vehicle spent 224 days and 9 hours in space during the first flight of the X-37B. Boeing Phantom Works built a second vehicle that orbited Earth for 468 days and 13 hours after launching in March 2011. The duration and objectives of the OTV-3 mission are classified and the payloads that are flown inside the X-37’s Payload Bay are secret as well. After launch, Satellite Trackers around the world will watch potential Low Earth Orbit slots to identify the vehicle and try to track it throughout its mission, observing the orbit changes the X-37B is known to make from previous flights. According to the US Air Force, the exact duration of the mission depends on the progress of the experiments the vehicle is flying.

Once its mission its complete, the X-37B will return to Vandenberg Air Force Base or the Kennedy Space Center for a landing. The Shuttle Landing Facility at KSC is not yet an active landing site for the X-37B, but the Air Force is currently assessing the Space Coast Runway for use by the X-37B. These assessments could be done in time for the landing of OTV-3.

Visit our X-37B SpacecraftOverview more information about the vehicle, its development and its previous missions.

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